The purpose of this film was to show employees, back in 1951, how calls were automatically switched through an SxS office.

This film gives a general appreciation of the importance, complexity, and cost of switching equipment in an average 1950s telephone office. The path of a call is illustrated as it runs through a demonstration unit. "Careful adherance to Bell System maintenance practices" is stressed. While this is only part I, Part II eventually showed the equipment in various types of use, and Part II showed the internal circuit operations.

Switchers today are digital and look drastically different. These systems at this time were still not even transistorized, so this film shows a system that's not only years back in time, but many generations back in terms of technology.